/*
 *  Copyright (c) 2001 Sun Microsystems, Inc.  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *
 *  1. Redistributions of source code must retain the above copyright
 *  notice, this list of conditions and the following disclaimer.
 *
 *  2. Redistributions in binary form must reproduce the above copyright
 *  notice, this list of conditions and the following disclaimer in
 *  the documentation and/or other materials provided with the
 *  distribution.
 *
 *  3. The end-user documentation included with the redistribution,
 *  if any, must include the following acknowledgment:
 *  "This product includes software developed by the
 *  Sun Microsystems, Inc. for Project JXTA."
 *  Alternately, this acknowledgment may appear in the software itself,
 *  if and wherever such third-party acknowledgments normally appear.
 *
 *  4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA"
 *  must not be used to endorse or promote products derived from this
 *  software without prior written permission. For written
 *  permission, please contact Project JXTA at http://www.jxta.org.
 *
 *  5. Products derived from this software may not be called "JXTA",
 *  nor may "JXTA" appear in their name, without prior written
 *  permission of Sun.
 *
 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 *  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 *  DISCLAIMED.  IN NO EVENT SHALL SUN MICROSYSTEMS OR
 *  ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 *  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 *  USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 *  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 *  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 *  OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 *  SUCH DAMAGE.
 *  ====================================================================
 *
 *  This software consists of voluntary contributions made by many
 *  individuals on behalf of Project JXTA.  For more
 *  information on Project JXTA, please see
 *  <http://www.jxta.org/>.
 *
 *  This license is based on the BSD license adopted by the Apache Foundation.
 *
 *  $Id: PeerGroupID.java,v 1.2 2005/05/26 06:13:48 hamada Exp $
 */
package net.jxta.peergroup;

import java.net.URI;
import java.net.URL;

import java.net.MalformedURLException;

import net.jxta.id.ID;
import net.jxta.id.IDFactory;

/**
 *  This class implements a PeerGroup ID. Each peer group is assigned a unique
 *  id.
 *
 *@see        net.jxta.id.ID
 *@see        net.jxta.id.IDFactory
 *@see        net.jxta.peer.PeerID
 */
public abstract class PeerGroupID extends ID {

    /**
     *  The well known Unique Identifier of the world peergroup. This is a
     *  singleton within the scope of a VM.
     */
    public final static PeerGroupID worldPeerGroupID = new WorldPeerGroupID();

    /**
     *  The well known Unique Identifier of the net peergroup. This is a
     *  singleton within the scope of this VM.
     */
    public final static PeerGroupID defaultNetPeerGroupID = new NetPeerGroupID();


    /**
     *  Returns the parent peer group id of this peer group id, if any.
     *
     *@return    the id of the parent peergroup or null if this group has no
     *      parent group.
     */
    public abstract PeerGroupID getParentPeerGroupID();
}

/**
 *  Universal WorldPeerGroupID
 *
 */
final class WorldPeerGroupID extends PeerGroupID {


    /**
     *  The name associated with this ID Format.
     */
    final static String JXTAFormat = "jxta";

    private final static String UNIQUEVALUE = "WorldGroup";


    /**
     *  WorldPeerGroupID is not intended to be constructed. You should use the
     *  {@link PeerGroupID.worldPeerGroupID} constant instead.
     */
    WorldPeerGroupID() { }


    /**
     *  {@inheritDoc}
     *
     *@param  target  Description of the Parameter
     *@return         Description of the Return Value
     */
    public boolean equals(Object target) {
        return (this == target);
        // worldPeerGroupID is only itself.
    }


    /**
     *  deserialization has to point back to the singleton in this VM
     *
     *@return    Description of the Return Value
     */
    private Object readResolve() {
        return PeerGroupID.worldPeerGroupID;
    }

    /**
     *  {@inheritDoc}
     *
     *@return    The iDFormat value
     */
    public String getIDFormat() {
        return JXTAFormat;
    }


    /**
     *  {@inheritDoc}
     *
     *@return    The uniqueValue value
     */
    public Object getUniqueValue() {
        return getIDFormat() + "-" + UNIQUEVALUE;
    }


    /**
     *  {@inheritDoc}
     *
     *@return    The parentPeerGroupID value
     */
    public PeerGroupID getParentPeerGroupID() {
        return null;
    }


    /**
     *  {@inheritDoc}
     *
     *@return    Description of the Return Value
     */
    public URI toURI() {
        return URI.create(ID.URIEncodingName + ":" + ID.URNNamespace + ":" + getUniqueValue());
    }
}

/**
 *  Universal NetPeerGroupID
 *
 */
final class NetPeerGroupID extends PeerGroupID {


    /**
     *  The name associated with this ID Format.
     */
    final static String JXTAFormat = "jxta";

    private final static String UNIQUEVALUE = "NetGroup";


    /**
     *  NetPeerGroupID is not intended to be constructed. You should use the
     *  {@link PeerGroupID.defaultNetPeerGroupID} constant instead.
     */
    NetPeerGroupID() { }


    /**
     *  {@inheritDoc}
     *
     *@param  target  Description of the Parameter
     *@return         Description of the Return Value
     */
    public boolean equals(Object target) {
        // netPeerGroupID is only itself.
        return (this == target);
    }

    /**
     *  deserialization has to point back to the singleton in this VM
     *
     *@return    Description of the Return Value
     */
    private Object readResolve() {
        return PeerGroupID.defaultNetPeerGroupID;
    }

    /**
     *  {@inheritDoc}
     *
     *@return    The iDFormat value
     */
    public String getIDFormat() {
        return JXTAFormat;
    }


    /**
     *  {@inheritDoc}
     *
     *@return    The uniqueValue value
     */
    public Object getUniqueValue() {
        return getIDFormat() + "-" + UNIQUEVALUE;
    }

    /**
     *  {@inheritDoc}
     *
     *@return    The parentPeerGroupID value
     */
    public PeerGroupID getParentPeerGroupID() {
        return PeerGroupID.worldPeerGroupID;
    }

    /**
     *  {@inheritDoc}
     *
     *@return    Description of the Return Value
     */
    public URI toURI() {
        return URI.create(ID.URIEncodingName + ":" + ID.URNNamespace + ":" + getUniqueValue());
    }
}

